Winding a load, for example a load positioned on a pallet, by means of an extensible plastic film to unite the packages that form the load and also to protect the load is known in the art.
A particularly interesting situation is when the load is positioned on the pallet. In this situation the film engages both the load and the pallet simultaneously to enable a safe handling.
A known type of winding device relates to movable devices, both manual and automatic.
In short, these known devices comprise a column positioned on a ground base and a reel-holder roll that moves vertically along the column.
When a load of various packages must be formed or when a load must be wound on a pallet, the load must first be arranged on the same; this requires the use of a lifting apparatus (the height to be reached can in fact be considerable, even over two meters), with which the load is lifted (for example boxes or the like) and is arranged on the pallet.
When this step has been completed, a winding device of the known type is then used, which unwinds the extensible plastic film from a reel inserted on the reel-holder axis and winds it (manually or automatically) around the load and pallet. In order to allow a correct and sturdy winding, the reel-holder roll (with the axis parallel to the development in height of the column) slides upwards and vice versa along the column, so as to perform a plurality of turns of extensible film (each partially overlapping the previous one) around the combination of pallet and load.
A limitation already appears evident from the above description: the formation and winding of the load and pallet is relatively lengthy and requires the use of various devices, which must be free and available in the warehouse.
It should be considered, in fact, that the time required for preparing and winding a load, for example on a pallet, must be as short as possible, to avoid creating additional costs and also to rapidly prepare the goods for delivery.
With specific reference to the winding devices that are known in the art, in manual devices, the column is positioned on a stand with wheels, preferably swivel wheels, which is rotated around the load (and possibly also the pallet) for winding. Although altogether practical and relatively economical, these systems have the drawback of having an extremely reduced versatility of use, as they can only be used for the above indicated specific purpose.
As far as automatic devices are concerned, on the other hand, the column is rotatable with respect to the base, rotatably supported by a second column, fixed with respect to the base; in this case, in addition to the limitations common with manual winding devices, the cost and encumbrance are not only much higher, but there are also limitations associated with the engagement height of the plastic film on the pallet. For geometric reasons, in fact, only a small part of the pallet is wound by the plastic film, with the result that the unification between the pallet and load does not always have a satisfactory robustness.